


Vulnerabilty

by Rookblonkorules



Category: Assassination Classroom
Genre: Aftermath of Torture, Aftermath of Violence, Akabane Karma Needs a Hug, Akabane Karma-centric, Angst, Gen, Hostage Situations, Hurt Akabane Karma, Hurt/Comfort, Implied/Referenced Neglect, Kidnapping, Post-Traumatic Stress Disorder - PTSD, Protective Karasuma Tadaomi, Protective Korosensei, Some AU elements, Teacher-Student Relationship, Torture, Violence, Whump, probably
Language: English
Status: Completed
Published: 2020-11-11
Updated: 2020-11-11
Packaged: 2021-03-09 17:53:28
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 3,405
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27500317
Author URL: https://archiveofourown.org/users/Rookblonkorules/pseuds/Rookblonkorules
Summary: It's not the first time Class 3-E has been used against Korosensei, but it's the first time Karma has found himself going through it alone.
Relationships: Akabane Karma & Karasuma Tadaomi, Akabane Karma & Korosensei, Kayano Kaede & Shiota Nagisa
Comments: 25
Kudos: 163





	Vulnerabilty

**Author's Note:**

> I've been going through my old docs to find stories that were never finished and this was one of them. I started writing this when I had almost finished the Assassination Classroom manga and apparently never got around to completing it. There are likely some elements that don't fit into canon, both because it's been some time since I've read Assassination Classroom (also, I'm pretty sure I deliberately veered off course a few times) and also because I was never super into it (although I love Karma and Karasuma with every part of my soul) so I'm sorry for anything that's off or OOC, but I did my best!  
> I have some headcanons for what Karma's background must have been like and that is also referenced in this fic.

“Do you know why I took you, Karma-chan?” 

Shiro’s voice is smooth as honey when he speaks, but it still feels like nails on a chalkboard to Karma’s pounding head. 

Shiro doesn’t wait for an answer. Not that Karma can give him one. The drugs still haven’t worked their way through his system.

He’s on his back, on a cold metal table. Straps across his waist and both of his wrists and ankles hold him down.

They aren’t leather, but it takes him a moment to place what they actually are. 

Anti-sensei material.

_ Bait for Korosensei, _ is on the tip of his tongue. Or it would be if his mouth didn’t currently feel like it was stuffed full of cotton balls.

It would hardly be the first time someone had attempted to use Class-E against Korosensei in the attempt to assassinate him. 

This makes it the first time he’s been taken alone though.

This makes it the first time he’s ever felt this helpless. Or this terrified.

“I suppose you do.” The way Shiro talks, it’s like he’s speaking to himself, despite the literal captive audience Karma provides him with. “You’re a smart boy after all.”

Shiro stands over him now. 

“While her betrayal was... useful, there really wasn’t a chance that Kayano would successfully complete the assassination of your teacher.” 

Karma grimaces at the reminder of  _ Kayano  _ of all people turning on them in the way she did. 

“It did, however, provide the distraction I was looking for though. You make an excellent piece of cheese in my mousetrap.”

His hands land on either of his shoulders and Karma’s skin crawls. More than anything, he doesn’t want this man touching him, but he can’t do anything to stop it.

He hates this- this feeling of helplessness. Of vulnerability.

There’s a moment where Shiro pauses. In the first sign of unease that he’s shown since the start of this, one of his fingers taps against Karma’s shoulder. 

“We shouldn’t have long to wait.”

That much was obvious from the start. Karma assumes that Shiro has taken some steps to cover their tracks in order to keep Korosensei from finding them too soon, but there’s still only so long you can keep yourself hidden from a being hunting at mach 20. 

Shiro steps away from Karma.

“You may want to sit tight, Karma-chan. These next moments won’t be pleasant for you.”

And that’s when Karma knows- whatever plan Shiro has to take out Korosensei, Karma isn’t meant to survive it. 

True to Shiro’s word, it doesn’t feel like very long before a yellow blur whooshes into the room.

“I’m very sorry you had to be put in this position, Karma-kun.” Korosensei is at his side before he has the time to blink. He moves to undo his bindings. “I’ll have you out of here in-”

“Wait-” Karma struggles to get the word out around a tongue that feels far too thick, but Korosensei holds up tentacles that have already started to disintegrate. 

“Oh, dear. Anti-sensei matter. This certainly complicates getting you out of here, Karma-kun.”

He doesn’t get a chance to say anything else. 

Electricity courses through the table underneath Karma and every nerve ending comes alive with terrifying clarity. 

He is on fire. 

He arches his back and  _ screams,  _ but there’s no escape. 

“Karma!” Korosensei’s voice barely registers in his head. 

Just as quickly as it came, the pain is gone. 

Karma is left struggling for breath, muscles trembling. Much to his horror, tears are already streaming down his face. 

He can’t stop twitching and everything feels fuzzy.

Korosensei appears in his field of vision, a distorted blob of yellow that hovers anxiously above his face. 

His fingers are spasming uncontrollably. He coughs, clenching and unclenching his fists.

“-your options, Reaper.” Someone is speaking and it takes him a moment to place that it is Shiro. 

“Karma-kun.” Korosensei’s voice is more somber than Karma thinks he’s ever heard it before. “I’m sorry.”

Karma doesn’t know what he’s talking about. Maybe it has something to do with the way he can’t seem to connect his thoughts. 

Something is tugging at the restraints at his wrists and he gets his eyes to travel down. 

“What--?” He can barely choke the word out. “What’re… you doing?”

Damnit. 

He hates the obvious slur in his voice, but he can’t stop it, can’t do anything about it- not when he feels so leaden, like a bowling ball is sitting inside his skull.

“I will get you out of this, Karma-kun,” Korosensei’s tone doesn’t change, despite the damage to his appendages, “even at the detriment to myself.”

And Karma wants to ask him why- why is he doing this, when he’s clearly hurting himself? Why him, when every other adult in Karma’s life has already let him down?

He can’t get his tongue to move when the first strap comes undone. 

Shakily, Karma lifts his hand, fumbling with the strap around his other wrist. He still feels heavy and uncoordinated and getting his fingers to cooperate is near impossible, but he keeps going. 

Finally, it comes undone and he struggles to sit up to get to his ankles. 

Korosensei helps him, wrapping a tentacle around the base of his shoulders. 

Karma hates this. Hates the way he actually needs the support because he’s too exhausted and too shaky to support himself. Hates that he actually wants this contact with Korosensei, that he feels like at any point now he might start crying. 

He just wants to rest here, head against Korosensei’s shoulder, and breathe, but he can’t.

He can’t because Shiro is here to kill Korosensei and Karma will die as well. He tries to lean forward, reaching for his ankles, but a tentacle wraps around his wrist gently, but firmly.

“You’re injured, Karma-kun. Let me.”

“You can’t!”

Is he trying to hurt himself further? What if the damage becomes irreparable? 

...since when has Karma cared?

All things considered, even taking his regenerative abilities into consideration, allowing himself to take this kind of damage won’t help either one of them in this situation. 

Korosensei doesn’t pay his protest any mind. It makes Karma want to scream. How can he be so  blasé about something like this?

His ankles are freed. 

Karma wobbles when Korosensei helps him off the table.

This doesn't make any sense.

Is Shiro really going to just let Korosensei rescue him? Is this something else and not an assassination attempt?

He doesn’t like any of this.

Karma has only been on his feet for about a second when it hits him with enough force to nearly knock him off his feet. Would have knocked him off his feet had it not been for Korosensei’s steadying tentacle around him.

It’s like a force equal to that of a sledgehammer has just slammed him in the gut.

As it is, Karma can’t hear anything beyond the blood rushing in his ears and his own screams.

It feels like he’s being shaken apart, organs shattered and muscles torn. 

The taste of copper fills his mouth and he realizes that he has bitten his own tongue. 

And then Koro-Sensei is there, body enfolding Karma’s own.

And things… lessen. 

“Karma,” Koro-sensei says, beady eyes boring into his own, and it sounds like his voice is coming to him from several feet underwater.

His ears must have been damaged in the attack.

“I will die before I allow one of my students to do so in my place.”

It is here that Karma recognizes the brilliance of this plan Shiro has concocted.

With his body folded around Karma to protect him, Koro-sensei can’t do a thing to protect himself. 

If Karma doesn’t stop this, Koro-sensei will die here.

_ Isn’t that the point? _ a nasty little voice in his head points out.  _ Assassinate Koro-sensei, save the world? _

But Karma realizes he doesn’t want Koro-sensei to die, least of all here in this place. 

_ He has to die, _ the voice reminds him.  _ It’s him or the earth. _

Maybe not. 

Nagisa had mentioned wanting to save him. Not that Karma had put much stock in its possibility at the time. 

Maybe not, but that doesn’t seem to be a line of thought that’s at all productive considering the circumstances.

There’s no way for him to stop this. 

He bites his lip to keep from crying out, fingers twisting in Korosensei’s tunic.

Korosensei seems to sense this and holds him a little tighter. The gesture is oddly comforting. 

And then- it stops. 

Karma gasps, lurching in Korosensei’s arms, and the two of them slide bonelessly to the ground. 

For a moment, it’s all Karma can to just lie there, shaking in his teacher’s arms.

“Are you two alright?”

Korosensei sighs directly above him. “You were a little slow, Karasuma-san. I was worried”

_ Karasuma-sensei is here too? _

“Is he alright? Are you alright? Let me take him. You’re a mess.”

Korosensei shifts and Karma wants to protest when he finds himself exchanging hands, but then his eyes take in the damaged state of his teacher for the first time. 

Korosensei’s posture is slumped, flesh dripping like melted candle wax. The side of his head has caved in and half his face droops. He looks like he’s just had a stroke. Or something. But his mouth still curves into a smile. Like nothing in the world in wrong with him. 

Karma feels sick.

“K-koro-” His throat hurts when he tries to speak. 

“I’ll be fine,” Korosensei says, far too cheerfully. He waves a tentacle in the air dismissively. 

Karma grits his teeth and wants to tell him to stop. To stop putting on this act. 

It’s annoying. 

It’s more than annoying. 

Karma doesn’t understand why the sight of his teacher in such a state has left him so shaken. Isn’t the entire point of the assassination classroom taking out Korosensei?

He’s still spasming and everything around him is growing fuzzier. 

He hasn’t quite shaken the aftereffects of whatever the shock he received was.

“You’d better get him out of here, Karasuma-san. I’m afraid I’m in no shape to move at Mach 20 right now. Even if I were, with him in this state, it would hardly be a good idea.”

“Right.”

The world greys. Korosensei fades to nothing more than a lemon-yellow blur.

“Karma? Karma!”

* * *

Waking up to white walls and the smell of antiseptic isn’t something Karma wants to make a habit of. 

He stirs and feels a pinch in the crook of his arm. He’s hooked to an IV line. 

Out of habit, he reaches to take it out and notices the bandages swathing his arms from wrists upward, disappearing under the sleeve of his hospital gown.

“Don’t touch that.” Karasuma-sensei sets down his book and uncrosses his leg, leaning forward. 

Karma blinks. 

How long has he been here? He really didn’t have Karasuma-sensei marked down as any sort of worrier, so… why was he here?

Karasuma-sensei must sense the question that’s on his mind, because he answers before Karma even has a chance to ask. 

“We figured it would be a good idea to have someone with you. Just in case.” His eyes travel down to the bandages. Something about his expression makes Karma want to hide the sight of them. “You had some pretty bad burns.” Then what’s in his IV line must be some sort of painkiller. “The nurses said there’ll probably be some scarring.”

“So?” Karma curls his fingers into a fist, relishing the power he has over his own limbs. “I’ll just look even more badass.”

The corner of Karasuma-sensei lips twitches, like he’s trying hard not to smile. He clears his throat. 

“Korosensei couldn’t be here. For obvious reasons. But he was acting pretty worried about you.”

That doesn’t surprise Karma. 

Korosensei always acts worried when something happens to any of them. 

There’s something else weighing on his chest though and it has nothing to do with Korosensei.

“What happened to…?” A vice clamps around his chest.

“He’s dead.”

“What?” For a moment, Karma thinks he may have heard him incorrectly.

“I shot him.” Karasuma-sensei shifts, clasping his hands in front of him. “He was arrogant. He hadn’t expected anyone else to be accompanying Korosensei.”

“So…” It’s like a weight has been lifted from his chest. Maybe he was more afraid than he was willing to admit, even to himself.    
“You won’t have to worry about him again.” His eyes are scrutinizing Karma again. 

Karma meets his gaze levelly, doing his best not to squirm. 

“Your classmates wanted to see you. Korosensei thought it best that your bedrest remain unhindered.”

That explains why they haven’t already clamored outside in the hall. It’s something of a relief, though Karma is unused to the feeling of having anyone worried about him at all. 

He files that away under “not dealing with it presently.”

“Thanks, I guess.” What else is he supposed to say? He twists his fingers in the hospital sheets and stares at his knees.

He wonders if his parents know anything about what happened, wonders if finally,  _ finally,  _ this would have gotten their attention, but it’s probably better not to ask. It’s better to not ask and not to know than to know and be disappointed again because they  _ don’t care. _

It’s got to be pretty messed up when your parents don’t show up, but your assassin teacher does, right?   


Karma swallows down the bitterness the thought leaves him with. 

Thinking about that now won’t do him any good.

* * *

He enters the classroom and tries to ignore the nineteen sets of eyes all on him. 

“Karma-kun!” Korosensei sounds as delighted as ever. As though nothing has happened. “You’re just in time!”

No, he’s not. 

He came deliberately late to avoid the otherwise inevitable questions of his classmates. Even now, he’s avoiding Nagisa’s stare like it’s the plague itself. 

Karma hates this, this whole game of pretend they seem to be playing, but when he tries to think of something snarky to say, his tongue sticks to the roof of his mouth. 

Instead, he slides into his seat, dropping his bag to the floor. 

Even attempting to focus turns out to be a lost cause. His mind keeps sliding back to the past. 

Karasuma-sensei had told him not to push himself. 

He’s not pushing himself. He’s perfectly fine. 

A tremor runs through his fingers. Karma presses them together.

It should be easy to slip into his mask of condescending indifference.

It’s not, but he manages to keep himself together for the entirety of class time. 

He drags his feet when it finally ends, slowly sliding his books into his bag. It’s completely unlike him and he knows it will only leave anyone watching him (which is probably everybody) with more questions, but he can’t bring himself to care. 

Not one of his classmates has approached him yet.

_ Yet  _ being the operative word. They’ll give him space for now, but he knows they’re likely brimming with questions and concerns that Karma doesn’t want to be bothered with. 

Nagisa is waiting for him. Kayano stands right beside him. They’re waiting for him.

Damn it. 

There’s only so long Karma can stall when he’s putting his materials away. 

_ Just go,  _ he thinks, letting his eyes slide shut.  _ Just go. _

That’s too much to hope for, of course, and when he opens them again, the both of them are still there, still waiting. 

Karma sighs, slinging his pack of his shoulder, and makes his way over to them. He puts some effort into deadening his expression.

“Karma-” To his surprise, Kayano, not Nagisa, is the one who speaks. Her face is pained when she looks at him. “I’m sorry.”

Of all the things Karma had expected, an apology was not one of them. There aren’t many times Karma has been left speechless by things his classmates have said and done.

This is one of those times.

Kayano brushes a strand of hair behind her ear, clearly having trouble looking him in the eyes. 

“I realize now that I was just the distraction for what he was planning,” she says. “I had no idea…”

“It was his fault,” Karma says, swallowing thickly because he isn’t used to handing out reassurances. “Not yours.”

“Everyone was worried about you,” Nagisa says slightly, but there’s a soft undertone of… something else that Karma can’t place. 

“A wasted effort.” It’s far too difficult to plaster his trademark, wolfish grin in place, but he manages. “As you can see, I’m fine.”

He’s unused to people caring… this much. Enough to wait up for him in the hospital. Enough to wait for him after class.

His parents never seemed to care, no matter how much he acted up. He’s still not sure if they even know he’d been abducted. 

Not that he’s keen on sharing that information with them.

“Karma-kun!” Korosensei’s voice cutting in would almost be something of a relief if he didn’t know his teacher had the same concerns the rest of his classmates did. “A moment, please?”

Probably more so since Korosensei had actually been there when… Karma swallows and blocks out that thought before it can progress any further. 

“I know you must want to spend time with your friends, but I won’t keep you long.”

Karma hesitates. He doesn’t particularly want to, but, one way or another, Korosensei will find his way to talk to him.

Maybe he should just get it over with here, rather than his teacher tracking him all the way back home. 

“Is something wrong?” He aims for boredom over arrogance. That feels easier to fake. 

Korosensei folds his tentacles across his desk. “I know something must be wrong because you haven’t tried to kill me once. I’ve spent a lot of time getting to know you students. I know when something isn’t right.”

Is he really that transparent? He grimaces at the thought. 

“You can always talk to me,” Korosensei presses. “It doesn’t have to be now, but…”

Karma looks away. The room is growing suspiciously blurry around him. “There’s nothing to talk about.” He closes his fists so Korosensei won’t see the way his fingers tremble. 

“There’s nothing to be ashamed of either,” Korosensei counters. 

That gives Karma pause.

Ashamed? Is he ashamed?

“You did nothing wrong, Karma. You were used.”

That’s part of the problem. He’d been nothing more than a tool for someone else’s endgame. 

“Why?” Karma interrupts him. 

“Why?”

“You said you would die before allowing one of your students to do so in your place.” Korosensei’s words from before are repeating in his mind. It’s not the first time their teacher has vocalized such sentiments. It’s not the first time their teacher has acted on such sentiments. It’s the first time it’s felt this… real. 

Karma swallows thickly. “Why?”

“Is that what’s been bothering you?” Korosensei nods along as though it all makes sense. More to himself than Karma, he says, “It makes sense that that would bother you.”

Karma opens his mouth, ready to say something, but then Korosensei is  _ there  _ in a blur of color, tentacles on either shoulder. 

“Because I promised Aguri I would.” Karma flinches at that. He should have known… 

“But,” Korosensei continues before he allows Karma to draw his own conclusion, “that’s no longer true. I don’t want the world to be deprived of the people you will become.”   
“That’s sentimental crap.”

“Maybe so, but it could also be true.”

“Could be?” Karma doesn’t understand why this bothers him so badly. He’s vibrating with the force of his emotions. 

“I just want you to tell me why. Is that so hard?”

Korosensei is quiet for a good moment and Karma thinks he finally has him. This is the moment where he admits that it’s all a farce. 

“I care about you. I don’t want you to die. What will it take to convince you of that if I haven’t already?”

“I don’t know.” His fingers itch to dig into his scalp. His breathing is coming harsher and faster. “I don’t know.” 

Korosensei’s tentacles wrap around him and pull him close. 

Karma slumps bonelessly into the embrace. Something warm trickles down his face. 

“Karma,” Korosensei says softly. “I’m not leaving you.”

_ Yes, you are, _ Karma thinks, but, for once, he doesn’t say it.  _ When we kill you. Don’t lie.  _

Because that’s how it is.

Him or the earth. 

He lets his eyes slide shut. 

**Author's Note:**

> There is now a fic inspired by this one. *happy author tears* If you're still hungry for Karma whump, please go read and give the author some love!

**Works inspired by this one:**

  * [Strength](https://archiveofourown.org/works/28590447) by [tatsue akashiro (smol_demon_giyuu)](https://archiveofourown.org/users/smol_demon_giyuu/pseuds/tatsue%20akashiro)




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